Differences in Fine Structures between Normal and RNA-induced Drosophila Pole Cells

Fine structures were compared between normal pole cells and those induced in embryos that had been uv-irradiated and then injected with intact polar plasm or with poly(A)⁺RNA extracted from cleavage embryos. Nuclei in nomal pole cells were spherical. In contrast, those in the induced pole cells were deformed to variable extents depending on materials injected with. Polar granules were smaller in pole cells induced by injection of poly(A)⁺RNA than in normal pole cells. The size of polar granules in polar-plasm-induced pole cells was intermediate between those in poly(A)⁺RNA-induced and normal pole cells. Small polar granules were observed in posterior cells of embryos uv-irradiated, nevertheless those cells were columnar and with identical morphology to somatic cells. Nuclear bodies showed a similar tendency in size differences as observed in polar granules in three types of pole cells observed.     

Establishment of five human myeloma cell lines

Summary Five human myeloma cell lines, KMM-1, KMS-5, KMS-11, KMS-12- PE, and KMS-12-BM, have been established at Kawasaki Medical School since 1980. As the KMS-12-PE and KMS-12-BM lines were obtained from the same patient, these five cell lines have been derived from four patients with multiple myeloma. The five myeloma cell lines are stably growing at present in RPMI 1640 medium supplemented with 10% fetal bovine serum. They can also grow in a defined culture medium without serum. That these cell lines were, human myeloma cells was confirmed by the following findings. Ultranstructually, all five cell lines showed features characteristic of plasma cells. KMM-1 and KMS-11 cells secreted lambda and kappa chains into the culture medium, respectively, but the other cell lines produced no immunoglobulins. KMM-1 expressed cytoplasmic lambda antigen, KMS-5 showed cytoplasmic delta, and KMS-11 expressed surface kappa, whereas KMS-12-PE and KMS-12-BM cells showed no surface or cytoplasmic immunoglobulins. Regarding reaction with a monoclonal plasma cell antibody (PCA-1), four of the five lines were positive, the exception being KMS-5. Another monoclonal antibody (CD38), which also recognizes plasma cells, reponded to KMM-1, KMS-12-PE, and KSM-12-BM. KMS-5 cells expressed acute lymphoblastic leukemia antigens (CALLA). These data suggest that such lines as KMM-1, KMS-11, KMS-12-PE, and KMS-12-BM represent later stages of B-cell differentiation, and that KMS-5 represents a relatively early stage of B-cell differentiation. All the cell lines lacked Epstein-Barr virus nuclear antigen, showed abnormal karyotypes of human origin, and differed from each other in the isozyme patterns examined. Only KMS-5 was tumorigenic when transplanted subcutaneously into nude mice.     

Endogenous gibberellins in clover broomrape,a parasitic plant,and its host,clover: Dependency of the parasite on the host for gibberellin production

Endogenous gibberellins were analyzed from a parasitic plant, clover broomrape (Orobanche minor Smith), and its host, clover (Trifolium repens L.). Members of both the early-13- and the early-non-hydroxylation pathways were identified from both the parasite and the host (GA₁₂, GA₂₄, GA₉ GA₄, GA₄₄, GA₁₉, GA₂₀, and GA₁ from clover broomrape; GA₉, GA₄, GA₄₄, GA₁₉, GA₂₀, and GA₁ from clover). Quantitative analyses showed that GA₄₄ was present at high levels in both host and parasite. The similarity in the gibberellins suggests the possibility that the major gibberellins in clover broomrape are transported from clover. However gibberellins such as GA₅₈, GA₃₈, and notably GA₄₇ which was identified from a plant for the first time were detected only from clover broomrape, suggesting that the parasite may have the ability to produce at least those gibberellins     

Change in growth kinetics of hybridoma cells entrapped in collagen gel affected by alkaline supply

The growth yields for glucose and glutamine of murine hybridoma cells entrapped in collagen gel particles were examined during the growth phase. The immobilized hybridoma cells were cultivated in a fluidized bed fermenter where the medium was circulating to supply oxygen separately. Procedures to supply an alkaline solution for adjusting the pH level strongly affected the growth yields. A direct supply of the alkaline solution to the cultivation system reduced both the growth yields for glucose and glutamine, probably due to a local increase in pH level. On the other hand, when fresh medium in which the pH was adjusted to around 8.5 was added to the cultivation system, the growth yields were unchanged even at the same pH level as when direct alkaline supply was used. These results suggest that an indirect alkaline supply could be recommended to ajust the pH level when using medium-circulating-fermenters.     

Immunocytochemical localization of thrombomodulin in the aqueous humor passage of the rat eye

 This report describes the distribution and localization of thrombomodulin (TM) in the rat eye by light and electron microscopic immunocytochemistry. In addition to the endothelium of the entire vasculature, TM was found on the non-vascular structures lining the cavities of the posterior and anterior chambers and the limbus. TM was localized on the basal, lateral, and apical plasma membranes of the inner and outer ciliary epithelium, and the posterior iris epithelium in which there was no polarized expression of TM. In the anterior chamber, TM was localized on the luminal surface of the corneal endothelium, but was negative on the anterior border layer of the iris, which is composed of a discontinuous layer of fibroblasts and collagen fibers. Thus, TM was present at sites of cell-to-cell contact. TM was also present on the endothelia of the trabecular meshwork and the Schlemm’s canal in the limbus. TM was localized not only on the luminal plasma membrane, but also on the cytoplasmic giant vacuoles in the endothelial cells of the Schlemm’s canal. These findings extend the importance of anticoagulant mechanisms to the systems of secretion, circulation, and drainage of the aqueous humor. Accepted: 18 March 1997     

Precursors of monoamine-storage organelles in developing megakaryocytes of the rat

Summary Identification and distribution of the precursors of aminestorage organelles in rat megakaryocytes during cell maturation were studied, using the uranaffin reaction for adenine nucleotide. The precursors of the amine-storage organelles appeared as 200–300 nm vesicles having an uranaffin electron dense granule, whereas they appeared as empty vesicles by conventional glutaraldehyde-OsO₄ fixation. X-ray probe microanalysis confirmed the existence of U and P in the uranaffin reaction positive vesicles. The precursors appeared in the immature megakaryocytes, especially at the trans(mature) face of the Golgi apparatus, and rapidly increased in number in the maturing cells. The size of the uranaffin granules in the precursory organelles increased gradually during cell maturation and became almost equivalent to the dense body of blood platelets in the final stage of cell maturation.     

Insulin binds to type V collagen with retention of mitogenic activity

The abilities of eight extracellular matrix proteins, fibronectin, vitronectin, laminin, and collagen types I, II, III, IV, and V to bind insulin were examined by binding studies with insulin conjugated with peroxidase. At a physiological pH and ionic strength, type V collagen bound to insulin most strongly. The other types of collagen, laminin, and vitronectin also bound insulin with affinity lower than that of type V collagen. The insulin-binding site of type V collagen was in a 30-kDa CNBr fragment of the alpha 1 (V) chain. Analysis of the amino acid sequence showed that this 30-kDa fragment was identical to the heparin-binding fragment of type V collagen. The insulin-binding sites of laminin and vitronectin were located in the A chain and in the heparin-binding domain, respectively. Insulin bound to type V collagen stimulated the synthesis of DNA by mouse mammary tumor MTD cells, indicating that bound insulin retained mitogenic activity.     

Cytochemical evidence of the origin of the dense tubular system in the mouse platelet

Summary Glucose-6-phosphatase (G6Pase) was used as a marker enzyme for the endoplasmic reticulum in mouse megakaryocytes and platelets. G6Pase activity was localized in the dense tubular system of the platelets. Enzyme activity was also observed in the nuclear envelope, and in the rough endoplasmic reticulum of the megakaryocytes. However, the Golgi apparatus of the megakaryocyte was never involved. The present study has added new cytochemical evidence for the hypothesis that the dense tubular system of the platelet originates from the endoplasmic reticulum of the megakaryocyte.     

Fine structural distribution of the surface-connected canalicular system in frog thrombocytes

Summary The existence of the surface-connected canalicular system (SCCS) has been demonstrated in semithick sections of the frog thrombocytes by the use of a high voltage electron microscope. The SCCS of the thrombocytes in Rana catesbeiana and Rana nigromaculata consists of numerous canaliculi and vesicles with a diameter of 250 nm, which join with one another to make a complex network throughout the cytoplasm. Although the SCCS of Xenopus laevis fits well into the pattern described in Rana catesbeiana, the diameter of the canaliculi of the SCCS is about 500 nm. The results of this study suggest that the SCCS is a specific organelle of the thrombocyte system common to submammals and mammals.